[INFO] cloning repository https://github.com/gsps/librustc_hair
[INFO] running `Command { std: "git" "-c" "credential.helper=" "-c" "credential.helper=/workspace/cargo-home/bin/git-credential-null" "clone" "--bare" "https://github.com/gsps/librustc_hair" "/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2Fgsps%2Flibrustc_hair", kill_on_drop: false }`
[INFO] [stderr] Cloning into bare repository '/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2Fgsps%2Flibrustc_hair'...
[INFO] running `Command { std: "git" "rev-parse" "HEAD", kill_on_drop: false }`
[INFO] [stdout] 955f23fa942253c05a73478aa575b498c7fb1a8e
[INFO] testing gsps/librustc_hair against 1.47.0 for beta-1.48-1
[INFO] running `Command { std: "git" "clone" "/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2Fgsps%2Flibrustc_hair" "/workspace/builds/worker-7/source", kill_on_drop: false }`
[INFO] [stderr] Cloning into '/workspace/builds/worker-7/source'...
[INFO] [stderr] done.
[INFO] validating manifest of git repo https://github.com/gsps/librustc_hair on toolchain 1.47.0
[INFO] running `Command { std: "/workspace/cargo-home/bin/cargo" "+1.47.0" "read-manifest" "--manifest-path" "Cargo.toml", kill_on_drop: false }`
[INFO] started tweaking git repo https://github.com/gsps/librustc_hair
[INFO] finished tweaking git repo https://github.com/gsps/librustc_hair
[INFO] tweaked toml for git repo https://github.com/gsps/librustc_hair written to /workspace/builds/worker-7/source/Cargo.toml
[INFO] crate git repo https://github.com/gsps/librustc_hair already has a lockfile, it will not be regenerated
[INFO] running `Command { std: "/workspace/cargo-home/bin/cargo" "+1.47.0" "fetch" "--locked" "--manifest-path" "Cargo.toml", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-7/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-7/source:/opt/rustwide/workdir:ro,Z" "-v" "/var/lib/crater-agent-workspace/cargo-home:/opt/rustwide/cargo-home:ro,Z" "-v" "/var/lib/crater-agent-workspace/rustup-home:/opt/rustwide/rustup-home:ro,Z" "-e" "SOURCE_DIR=/opt/rustwide/workdir" "-e" "CARGO_TARGET_DIR=/opt/rustwide/target" "-e" "CARGO_HOME=/opt/rustwide/cargo-home" "-e" "RUSTUP_HOME=/opt/rustwide/rustup-home" "-w" "/opt/rustwide/workdir" "-m" "1610612736" "--user" "0:0" "--network" "none" "rustops/crates-build-env@sha256:d92eaeed33fa75130ca1ee6c8a01d1ffb62bac859dfdfb3450e3e5d1c0146529" "/opt/rustwide/cargo-home/bin/cargo" "+1.47.0" "metadata" "--no-deps" "--format-version=1", kill_on_drop: false }`
[INFO] [stdout] 10a6311f2e4358185d115b213d3df74ecd7f24ab7d6293387a909fd00ed54026
[INFO] [stderr] WARNING: Your kernel does not support swap limit capabilities or the cgroup is not mounted. Memory limited without swap.
[INFO] running `Command { std: "docker" "start" "-a" "10a6311f2e4358185d115b213d3df74ecd7f24ab7d6293387a909fd00ed54026", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "inspect" "10a6311f2e4358185d115b213d3df74ecd7f24ab7d6293387a909fd00ed54026", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "10a6311f2e4358185d115b213d3df74ecd7f24ab7d6293387a909fd00ed54026", kill_on_drop: false }`
[INFO] [stdout] 10a6311f2e4358185d115b213d3df74ecd7f24ab7d6293387a909fd00ed54026
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-7/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-7/source:/opt/rustwide/workdir:ro,Z" "-v" "/var/lib/crater-agent-workspace/cargo-home:/opt/rustwide/cargo-home:ro,Z" "-v" "/var/lib/crater-agent-workspace/rustup-home:/opt/rustwide/rustup-home:ro,Z" "-e" "SOURCE_DIR=/opt/rustwide/workdir" "-e" "CARGO_TARGET_DIR=/opt/rustwide/target" "-e" "CARGO_INCREMENTAL=0" "-e" "RUST_BACKTRACE=full" "-e" "RUSTFLAGS=--cap-lints=warn" "-e" "CARGO_HOME=/opt/rustwide/cargo-home" "-e" "RUSTUP_HOME=/opt/rustwide/rustup-home" "-w" "/opt/rustwide/workdir" "-m" "1610612736" "--user" "0:0" "--network" "none" "rustops/crates-build-env@sha256:d92eaeed33fa75130ca1ee6c8a01d1ffb62bac859dfdfb3450e3e5d1c0146529" "/opt/rustwide/cargo-home/bin/cargo" "+1.47.0" "build" "--frozen" "--message-format=json", kill_on_drop: false }`
[INFO] [stdout] 0ad22eccff690c4abedaa9248d5fea503c3375c9de2eeea3a2f4322fc19e2530
[INFO] [stderr] WARNING: Your kernel does not support swap limit capabilities or the cgroup is not mounted. Memory limited without swap.
[INFO] running `Command { std: "docker" "start" "-a" "0ad22eccff690c4abedaa9248d5fea503c3375c9de2eeea3a2f4322fc19e2530", kill_on_drop: false }`
[INFO] [stderr]     Blocking waiting for file lock on package cache
[INFO] [stderr]    Compiling smallvec v1.4.1
[INFO] [stdout] error[E0554]: `#![feature]` may not be used on the stable release channel
[INFO] [stdout]   --> /opt/rustwide/cargo-home/registry/src/github.com-1ecc6299db9ec823/smallvec-1.4.1/lib.rs:74:32
[INFO] [stdout]    |
[INFO] [stdout] 74 | #![cfg_attr(feature = "union", feature(untagged_unions))]
[INFO] [stdout]    |                                ^^^^^^^^^^^^^^^^^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] error[E0554]: `#![feature]` may not be used on the stable release channel
[INFO] [stdout]   --> /opt/rustwide/cargo-home/registry/src/github.com-1ecc6299db9ec823/smallvec-1.4.1/lib.rs:76:37
[INFO] [stdout]    |
[INFO] [stdout] 76 | #![cfg_attr(feature = "may_dangle", feature(dropck_eyepatch))]
[INFO] [stdout]    |                                     ^^^^^^^^^^^^^^^^^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] error: aborting due to 2 previous errors
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] For more information about this error, try `rustc --explain E0554`.
[INFO] [stdout] 
[INFO] [stderr] error: could not compile `smallvec`.
[INFO] [stderr] 
[INFO] [stderr] To learn more, run the command again with --verbose.
[INFO] running `Command { std: "docker" "inspect" "0ad22eccff690c4abedaa9248d5fea503c3375c9de2eeea3a2f4322fc19e2530", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "0ad22eccff690c4abedaa9248d5fea503c3375c9de2eeea3a2f4322fc19e2530", kill_on_drop: false }`
[INFO] [stdout] 0ad22eccff690c4abedaa9248d5fea503c3375c9de2eeea3a2f4322fc19e2530
